Mini Circuits ZFSC-2-5 as a splitter

I bought a Mini Circuits ZFSC-2-5 Power Splitter/combiner from eBay for use as an antenna splitter for one antenna for two radios, like you would use a Stridsberg multicoupler. Has anyone used one for this purpose, and what are your opinions of it? It seems to work okay, but I don't notice much difference between this and a cheap TV type splitter.

If I read the specs correctly, it seems that you could transmit into it a maximum power of one watt, whereas the Stridsberg is strictly for receiving.

Here is a link to the specs: https://www.minicircuits.com/pdfs/ZFSC-2-5+.pdf

Compared to the Stridsberg passive couplers, it appears that the Mini Circuits splitter/combiner has better specs for both port-to-port isolation, and for insertion loss. I use a few of Mini Circuits devices with my test equipment, including a couple of their directional couplers, and I've been very happy with their performance.

No matter what the specs say about power input, I would avoid hooking a transmitter up to it, unless you were sure you were only going to operate in the 100mW or less range.

W4KRR said:

Has anyone used one for this purpose, and what are your opinions of it? It seems to work okay, but I don't notice much difference between this and a cheap TV type splitter.

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Yes, I've used that and similar Mini-Circuits splitters. They're well built, and meet published specs.

As to the difference between it and a cheap TV splitter, both are going to give you the theoretical 3+ dB loss. That's physics. What you get by paying more for a Mini-Circuits splitter is consistent documented performance, probably better return loss over the published specs, better connectors than F type, and probably better port isolation.

The mini-circuit one are more suited for measuring work and on a test bench as it has the exact same levels out on both ports and the phase seems to be unaltered, which are not at all important if used in any other application as with scanner reception. Isolation are good at 25dB and my chinese $5 splitter measured 22dB at 400Mhz so pretty much the same.

BNC connectors are also used in test and lab enviroments when you connect and disconnect a lot and you eventually have to replace the connectors as they wear out. For home use where you might connect and disconnect once a day you can use F connectors who are more reliable in a fixed installation.

Conclusion: If you need a splitter at your test bench then choose the more calibrated one with BNC connectors but for permanent scanner use you would choose the cheaper CATV F connector one.

/Ubbe

N9PBD said:

Compared to the Stridsberg passive couplers, it appears that the Mini Circuits splitter/combiner has better specs for both port-to-port isolation, and for insertion loss. ...

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Be sure you understand that the total loss for the Mini-Circuits is 3.3 to 4.1 dB (not just the small insertion loss). This is about the same as a cable TV device. And it is passive. The Stridsberg *active model* is an active device and has slight gain rather than loss and I suspect better isolation. The Stridsberg comes in models other than just a 1 to 2 splitter (such as 1 to 4) whereas using two Mini-circuits to the that would be a 6 to 8 dB loss. I would be very careful about possibly suggesting a Mini Circuits splitter is a better choice than the Stridsburg. If I were going to use a Mini-Circuits, I would be likely to use one of their pre-amps before the splitter--but an active Stridsberg does similar already for you.

I have tried all 3 Cheap TV Mini-Circuits and Stridsberg and the Stridsberg runs circles around the other two providing me 16 output ports for my 16 scanners sharing the same antenna.
Yes I tried a variable amp on the CHEAP TV SPLITTER and also on the MINI-CIRCUITS SPLITTER I used the same feedline and antenna and my range increased on all my scanners using the 3 Stridsbergs feeding my system. You get what you pay for.

With a low noise amplifier and CATV chinese splitter I get better results than with my Stridsberg MCA204.

I can also measure the isolation between ports. The MCA204 outer port and the next one to it are connected to the same splitter transformer (pic 1), as are the two ones at the other side. These two transformers are then connected to a common splitter transformer and going thru both transformer (pic 2) will give the most isolation.
I also measure a $5 chinese CATV 1-2 splitter with (pic 3) and without (pic 4) a 50 ohm load on the input port.

/Ubbe

Working in the radio industry I understand what you are saying. The only fact I have is I gained range with my scanners.

Ubbe said:

With a low noise amplifier
/Ubbe

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Which low noise amplifier? Source/link?

I have several and you only have to look at the specs that the noise figure is 2dB or less and can handle high levels of ip1 and ip3, at least the same as the Stridsberg and you'll get better performance with much cheaper stuff and also have the option to gain much more performance if you move the amplifier to the base of the antenna.

https://www.ebay.com/sch/iseeabluewhale/m.html?item=282193326539

/Ubbe

I have to say that a Stridsberg multicoupler will enhance most scanners reception compared to connecting a coax directly to a scanner, as will almost any $10 amplifer as most scanners seems to have worse specs than external amplifiers. I haven't used my Stridsberg for 8-10 years as other solutions where better and I also accidently touched the PTT on a radio connected to it when I disconnected it and had to change the transistor in it but the transformers could have been damaged as well and don't show the same spec as it should, which Stridsberg says is more than 22dB isolation.

Ubbe said:

https://www.ebay.com/sch/iseeabluewhale/m.html?item=282193326539

/Ubbe

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Can I use one of those as a TV antenna amp?

scanmanmi said:

Can I use one of those as a TV antenna amp?

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Yes.

They have better specs than any dedicated tv antenna amplifier but you have to arrange some kind of box for it and they usually come with sma connectors so you'll need adapters or cables with sma connectors fitted and you have to power the amplifier with DC voltage. Either they have a direct power in using usb or 12v or can be powered from the coax, which is the best if you install the amplifier at the antenna. The bias-t modules you can buy to power thru coax are a bit expensive for what they do, so you usually have a splitter with an extra free port in the room and power that port thru a choke coil that let DC voltage through but stops the RF. Usually a splitter has at least one port that are labeled power thru that you use. If the CATV splitter doesn't say anything about power thru then it can't be used.

/Ubbe

Not suggesting anyone buy this one...

https://www.ebay.com/itm/Ultra-Line...m=282929276479&_trksid=p2060778.c100290.m3507

But I've had very good results with it. It uses this amplifier...

https://www.minicircuits.com/WebStore/dashboard.html?model=PGA-103+

I would also recommend the SPF5189Z based amps, nornally less than $10 on ebay and they have good IP3, P1db and 0.6db NF, like this one:-

https://www.ebay.com/itm/LNA-50-400...536504&hash=item2a903b4ea0:g:IywAAOSw2N1Z1gM5

Be carfeul what you power them with though, noisy USB PSUs and USB batteries can introduce wide band noise.